PHIL 255: Philosophy of Mind

Week 2

2a, Other minds

What do you know about other minds?

1. People you know well: family & friends?

"You don't know me at all."

2. Other genders?

3. Mentally ill: psychopaths, autism, manic/depressive

4. How do you infer what is going in other minds?

5. Capgras syndrome: delusion that a close relative or friend has been replaced by an imposter.

The problem of other minds

1. You know your own mind by introspection

2. You cannot introspect other minds

3. So maybe you don't know anything about other minds?

Compare other skeptical problems: complete skepticism, doubts about the external world.

Solutions to the problem

1. Behaviorism

There is no mind: we can only talk about observable behavior.

B . F. Skinner: use stimulus/response manipulations to control behavior.

Ryle: don't talk about the ghost in the machine.

"You're fine, how am I."

"How can I know what I believe till I hear what I say."

Response: behaviorism cannot account for the nature of mind.

2. The Private Language Argument

Knowledge of one's own mind presupposes knowledge of other minds, or else you would not even have the concepts to talk about them.

Response: Why not? Why not form a conceptual scheme from your own experience?

3. Analogy:

You are like me in many respects: behavior, appearance, physiology

I have a mind.

So, by analogy, you have a mind too.


(1) the analogy is weak because of differences in form of knowing: first person knowledge is very different from second person.

(2) Analogy is a weak form of argument.

Empathy is a very important kind of analogy, in which I understand your situation by an emotional analogy to my own previous situation.

See Barnes & Thagard, 1997.

4. Inference to the best explanation

The best explanation of your behavior is that you have a mind.

What are the alternative hypotheses? E.g. you are a robot, or a zombie.


(1) Is the hypothesis that you have a mind really the best explanation?

(2) Is the best explanation good enough?

(3) What about analogies?

5. Combine analogy and inference to the best explanation

One of the reasons that the hypothesis that you have a mind is the best explanation of your behavior is that analogously the hypothesis that I have a mind is the best explanation of my behavior.

Analogy is one of the criteria for determining the best explanation, along with how much is explained and simplicity.

Additional evidence: we can tell from brain scans that your brain has pretty much the same structure as mine.

2b Animal beliefs

Discussion: Who has minds?

People, chimps, dogs, squirrels, crocodiles, goldfish, snails, grasshoppers, jellyfish, trees, bacteria, viruses, rocks.

What convinces you that there is a mind? Language? Planning?

Animal belief: arguments

Davidson's argument (p. 72):

1. A creature can have a belief only if the belief is positioned in a network of beliefs.

2. Animals lack belief networks.

3. So, animals lack beliefs.


1. Evaluation of assumptions 1 and 2. Do animals really lack belief networks?

2. Is belief possession the best explanation of the behavior of animals?

Animals differ from us in knowledge representation a lot.

E.g. dogs: smell.

IBE should not allow adoption of a weak explanatory theory.

What are beliefs?

Beliefs are propositional, sentence-like. This may not be the best way to describe animals, and may even be misleading about humans.

Propositional attitudes. Is thought only in words? Other kinds of representation: visual, olfactory, auditory images.

Parrots have been trained to make same/different judgments? Do they have beliefs about sameness and difference?

Compare the issue of animal beliefs with the Whorf hypothesis: other cultures with very different languages have very different thought processes.


Do animals have the same kinds of emotions that people do?

Do emotions require beliefs?

Intentionality: aboutness

What is the content of beliefs? Beliefs relate not only to other beliefs, but also to the world? How does language hook on to the world? How does mind hook on to the world? Do animals have beliefs that are about the world?


Gallup result: only chimps recognize themselves in mirrors. What is it to be aware of yourself? How important is self-consciousness to having a mind?

Conjecture: self-representation depends on spindle neurons, which are found only in humans and great apes.

Phil 255

Computational Epistemology Laboratory.

Paul Thagard

This page updated Sept. 19, 2005.